0:00
All right.
00:01
So to begin, we're asked to find the sample mean and the sample standard deviation, where the sample mean we find by summing up all of our data and dividing by the sample size.
00:14
So what we'll do is copy down the data that we have.
00:17
So it's just going to be one moment here.
00:23
Okay.
00:23
So we have our data shown there.
00:26
And then i'm just going to use the capabilities built into my software here for finding the mean.
00:32
That's 22 .125 for the mean value.
00:36
And then for the sample standard deviation s, we would want to here to actually get the result.
00:46
But we have that the sample standard deviation is going to be equal to the square root of the sum, the difference between each data point and the mean value squared, divided by, since this is a sample, n minus 1.
01:01
So we find that when we do that, the result is going to be to three decimal places, 3 .182 roughly.
01:10
Then we're asked for the 90 % confidence interval.
01:15
I'll note that we can find a confidence interval by taking x bar plus or minus...